Hitching device



March-2d; 1945. wlN 2,371,662

HITCHING DEVICE Filed June 2, 1943 INVENTOR. Starling Wi nters BYC'. d 4' A TTORNEYS.

Patented Mar. 20, 1945 UNITED. STATES PATENT OFFICE M 1 I I 2,371,662. e 7 HITCHING DEVICE Starling Winters. Englewood, N. J. Application June 1943, Serial No. 489,359

Claims. (01. 230-3315) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G, 757) The invention described hereinmay be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention pertains to a novel device for hitching a towed vehicle to a tractor.

The principal object of the invention is to eliminate end play and side play due to looseness in the connection to the pintlefof the tractor. The damaging results of end play and side sway are well known, among which are breakage of vital parts and curtailment of the maximum safe speed. i

This object is accomplished by the action of a vise jaw movable in a lunette and mechanism whereby the initial pull on the lunettetightens the jaw against the pintlen This mechanism is preferably hydraulic and includes the pistons attached respectively to the lunette and the jaw. The cylinders for thepistons are in communication with each other only when pressure is exerted by the lunette-operated piston. The latter is so proportioned as to exertthe proper pressure on the other piston and the jaw carried thereby. This pressure'thus becomes trapped behind the jaw piston and secures the jaw substantially rigidly in its clamping position. The trapped pressure may be relieved by manually opening a check valve, whereupon thejaw piston and the jaw are retracted by the action of a spring which was previously compressed on the pressure stroke of the piston.

2, between which the rearward portionof the.

The invention is fully disclosed by way of example in the following description and in the accompanying drawing in which: A

Figure 1 is a topplan-view of the device, partly in section;

Figure 2 is a longitudinal verticalsection, partly in elevation, and

Figure 3 is an enlarged detail vertical section.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts'throughout;

Each of the figuresshows a main cylinder I lying on a horizontal axis l and formed with a reservoir 2 at a higher level so that the hydraulic fluid used in the system may flow by gravity from the reservoir to the cylinder as will presently be described. The cylinder is formed with a pair of lateral apertured flanges 3 or other suitable means for attaching the device to the A-frame of the towed vehicle. The top of the reservoir is fitted with a cover plate 4 which may be welded in place, and in the plate isinserted a fill plug 5. h e

A vise cylinder I is extended forwardly and ooaxially from the main cylinder I and may be integral therewith. Suitable reinforcing ribs 8 are provided along the cylinder I. The cylinder I is extended somewhat into the'cylinder I by means of a, thickened wall portion 9 within the latter, as shown in Figure 2.

In the vise cylinder "I is mounted a vise piston ID from which extends atubular piston rod II through the forward endof the cylinder. The piston III has a suitable packing I2 fitted in the cylinder 1. On the forward or' external end of the rod II is secured a vise member I3 by screws I4. The forward end of the vise member carries a pin I5 on which is pivotally mounted a lunette visejawIB. p

A lunette piston rod II is slidably mounted in the tubular piston rod II, projecting forwardly therefrom into the vise member I3 and rearwardly for some distance into the main or lunette cylinder I. At the latter end, the piston rod I1 carries a piston I8 fitted in the cylinder I and having suitable packing I9. The rear end of the cylinder I is closed by a loosely fittedcap 20. The forward end of the piston rod I1 is formed with a lunette 2| enclosing the jaw I6. The vise member I 3 consists of a pair of arms, as shown in Figures 1 and lunette is received. I l

The rear end of the vise cylinder I within the lunette cylinder I has secured thereto a diaphragm plate 22 by bolts 23. This plate has a packing assembly 24 fitted around the piston rod I1 and secured by a retaining plate-25 andscrews 26. The rear end of the vise cylinder I communicates with the reservoir 2 through a passage 21 in the enlarged cylinder wall 9. In this passage isfitted a, check valve 28 extending into the reservoir and normally held closed by a spring 29.

Another passage 30extends from the passage 21 through the plate 22 to the cylinder I, and in this passage ismounted a check valve 3| opening towards the passage 21 and normallyheld closedby a, spring 32. A relief valve33 for the Y within the lunette 2| as shown. The lunette is then placed in the pintle 35 in the usual manner.

The tractor is then started, producing a pull on Before the the lunette andits pistonrod II. trailer vehicle moves forward, the lunette piston I8 advances, transferring fluid through the check valve 3| and passages 30,11 to the vise cylinder slidably mounted in the cover plate 4 and posi- A spring 3! dis-- tioned in line with the valve. in H posed in the cylinder 1 between its forward end and the piston Ill and which has previous lybeen compressed is now permitted to expand due to the relief of the cylinder 1 through the check valve 28. The piston rod I1 is thus retracted,

carrying with it the vise member I3 and vise jaw 16.

When the vise jaw has reached its limit within the lunette, the manual pressure on the plunger 36 is discontinued. The lunette is now lifted out of the pintle. Further pressure on the plunger 36 permits anotherrearward movement of the vise jaw in the manner described, and the jaw engages the rear end of the lunette to move the latter rearwardly. The rearward motion of the lunette piston l8 draws oil into the lunette cylinder'l from the reservoir through the relief valve 33, in preparation for the next hitching operation. The rear end of the cylinder I is vented beneath the loosely fitted cap 20.

It may now be seen that the initial-pull of the tractor on the lunette tightly clamps the pintle between the jaw l6 and the forward end of the lunette 2|. Side sway is a function of looseness at the pintle and is therefore-substantially eliminated because of the tight grip on the pintle.

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made withoutdeparting from the scope of the invention as indicated by the appended claims.

What I claim is:

1. A hitching device comprising a lunette, a

vise jaw movable in said lunette, means for ad vancing said jaw in the lunette, and an operative connection between said means and said lunette and operable-by a pull on said lunette to move said means and to thereby advance the jaw.

2. A hitching device comprising alunette, a vise jaw movable in said lunette, hydraulic means for advancing said jaw in the lunette, and an operative connection between said' means and 4.

said lunette and operable by a pull on said lunette to move said means and to thereby advance the jaw. j

3. A hitching device comprising a lunette, a

, vise jaw movable in said lunette, pistons attached respectively to said lunette and jaw, a lunette cylinder and a vise jaw cylinder for said pistons,

a one-way means of communication between said cylinders adapted to open under pressure from the lunette-operated piston, whereby to advance the other piston and said jaw relatively to said lunette. I

4. A hitching device comprising a lunette, a vise jaw movable in said lunette, pistons at tached respectively to said lunette and jaw, a lunette cylinder and a vise jaw cylinder for said pistons, a one-way means of communication be-- tween said cylinders adapted to open under pressure from the lunette-operated piston, whereby to advance the other piston and said jaw relatively to said lunette, manually releasable means for trapping pressure in said vise jaw cylinder, and a spring adapted to retract said jaw in said lunette on release of said means.

5. A hitching device comprising a lunette, a vise jaw movable in said lunette, pistons attached respectively to said lunette and jaw, a lunette cylinder and a vise jaw cylinder for said pistons, a one-way means of communication between said cylinders adapted to open under pressure from the lunette-operated piston, whereby to advance the other piston and said jaw relatively to said lunette, a spring in said vise jaw cylinder adapted to be energized on advance of 15 the piston attached to.said jaw, and manually releasable means for trapping pressure in said vise jaw cylinder in opposition to said spring.

6. A hitching device comprising a lunette, a

vise jaw movable in said lunette, pistons attached respectively to said lunette and jaw, a lunette cylinder and a vise jaw cylinder for said pistons, a one-way means of'communication between said cylinders adapted to open under pressure from the lunette-operated piston, whereb to advance the other piston and said jaw relatively to said lunette, a reservoir having a connection to said vise jaw cylinder, manually releasable means for trapping pressure in said vise jaw cylinder, and a spring adapted to retract said jaw in said lunette on release of said means.

7. A hitching device comprising a lunette, a vise jaw movable in said lunette, pistons attached respectively to said lunette and jaw, a lunette cylinder and a'vise jaw cylinder for said pistons, a one-way means of communication between said cylinders adapted to open underpressure from i the lunette-operated piston, whereby to advance the other piston and said jaw relatively to said lunette, a reservoir having a connection to said vise jaw cylinder, means for trapping pressure in said vise jaw cylinder, a spring adapted to retract said jaw in said lunette on release of said means, and a plunger mounted in said reservoir for releasing said means.

8. A hitching device comprising a lunette, a vise jaw movable in said lunette, pistons attached respectively to said lunette and jaw, alunette cylinder and a vise jaw cylinder for said pistons. a one-way means of communication between said the lunette-operated piston, whereby to advance the other piston and said jaw relatively to said lunette, a spring in said vise jaw cylinder'adapted to be energized on advance of the pistonattached to said jaw, a reservoir havinga connection to said'vise jaw cylinder, manually releasable means for trapping pressure in said vise jaw cylinder, and a spring adapted to retract the jaw in said lunette on release of said means.

9; A hitching device comprising a lunette, a vise jaw movable in said lunette, pistons attached respectively tosaid lunette and jaw, a lunette cylinder and a vise jaw cylinder for said pistons, a one-way means of communication between said cylinders adapted to open under pressure from the lunette-operated piston, wherebyto advance the other piston and saidjaw relatively to said lunette, a reservoir having a connectionto said vise jaw cylinder, manually releasable means for trapping pressure in said vise jaw cylinder, and a spring adapted to retract said jaw in said lunette on release of said means, and a relief valve between said reservoir and said lunette cylinder and adapted to open on reduced pressure in said cylinder.

cylinders adapted to open under pressure from 10. A hitching device comprising a lunette, a

vise jaw movable in said lunette, pistons attached respectively to. said lunette and jaw, alunette cylinder and a vise jaw cylinder for said pistons,

a one-way means of communication between said cylinders adapted to open under pressure from the lunette-operated piston, whereby to advance the other piston and said jaw relatively to said lunette, a reservoir having a. connection to said Gil vise jaw cylinder, means for trapping pressure in said vise jaw cylinder, a spring adapted to retract said jaw in said lunette on release of said means, and a plunger mounted in said reservoir for releasing said means, and a relief valve between said reservoir and said lunette cylinderrand adapted to open on reduced pressure in said cylinder.

STARLING WINTERS. 

